#include <iostream>
#include <queue>
#include <map>
#include <list>
#include <vector>
#include <string>
#include <limits>
#include <cassert>
#include <fstream>
#include <cstring>
#include <bitset>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdio>
#include <ciso646>
#include <array>
#include <set>

using namespace std;

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

#define inf 0x3f3f3f3f
#define uinf 0x3f3f3f3f3f3f3f3f
#define CLEAR(a) a = decltype(a)()
#define MP make_pair
#define ALL(a) (a).begin(),(a).end()
#define pii pair<int ,int>
#define pcc pair<char,char>
#define pic pair<int,char>
#define pci pair<char,int>
#define vs vector<string>
#define vi vector<int>
#define vii vector<vector<int>>
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define pi 2*acos(0.0)
#define INFILE() freopen("in.txt","r",stdin)
#define OUTFILE() freopen("out.txt","w",stdout)
#define ll long long
#define ull unsigned long long
#define eps 1e-14
#define FIN std::ifstream cin("D:\input.txt")

using namespace std;

#define int ll

signed main(void) {
	int N, M; cin >> N >> M;
	vector<int> A(N); for (auto &a : A) cin >> a;
	vector<int> K(N); for (auto &a : K) cin >> a;
	int diff = 0; //pay
	REP(i, N) diff += A[i] * K[i];
	diff -= M;
	if (diff < 0) {
		cout << -1 << endl;
		return 0;
	}

	vector<int> dp(A.back()*A.back(), uinf); // = お釣りの最小枚数
	dp[0] = 0;

	if (diff >= dp.size()) {
		int c = (diff - dp.size()) / A.back();
		++c;
		diff -= c*A.back();
		dp[0] = c;
	}

	REP(i, dp.size()) REP(j, A.size()) if (i - A[j] >= 0) 
		dp[i] = min(dp[i], dp[i - A[j]] + 1);

	if (dp[diff] >= uinf) cout << -1 << endl;
	else cout << dp[diff] << endl;
	return 0;
}